Use vpath directive

The vpath directive has two advantages over the VPATH variable:
1) it allows to skip searching of .o files; 2) the default semantics
are to append to the vpath, so there is no confusion between "VPATH=xyz"
and "VPATH+=xyz".

Since "vpath %.c %.h PATH" is not valid, I'm introducing a wrapper
macro to append one or more directories to the vpath.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

Makefile

@@ -24,7 +24,7 @@ configure: ;
 .PHONY: all clean cscope distclean dvi html info install install-doc \
 	recurse-all speed tar tarbin test build-all
 
-VPATH=$(SRC_PATH):$(SRC_PATH)/hw
+$(call set-vpath, $(SRC_PATH):$(SRC_PATH)/hw)
 
 LIBS+=-lz $(LIBS_TOOLS)
 

Makefile.hw

@@ -7,7 +7,7 @@ include $(SRC_PATH)/rules.mak
 
 .PHONY: all
 
-VPATH=$(SRC_PATH):$(SRC_PATH)/hw
+$(call set-vpath, $(SRC_PATH):$(SRC_PATH)/hw)
 
 QEMU_CFLAGS+=-I.. -I$(SRC_PATH)/fpu
 

Makefile.target

@@ -11,7 +11,7 @@ include $(HWDIR)/config.mak
 endif
 
 TARGET_PATH=$(SRC_PATH)/target-$(TARGET_BASE_ARCH)
-VPATH=$(SRC_PATH):$(TARGET_PATH):$(SRC_PATH)/hw
+$(call set-vpath, $(SRC_PATH):$(TARGET_PATH):$(SRC_PATH)/hw)
 QEMU_CFLAGS+= -I.. -I$(TARGET_PATH) -DNEED_CPU_H
 
 include $(SRC_PATH)/Makefile.objs
@@ -91,7 +91,8 @@ signal.o: QEMU_CFLAGS += $(HELPER_CFLAGS)
 
 ifdef CONFIG_LINUX_USER
 
-VPATH+=:$(SRC_PATH)/linux-user:$(SRC_PATH)/linux-user/$(TARGET_ABI_DIR)
+$(call set-vpath, $(SRC_PATH)/linux-user:$(SRC_PATH)/linux-user/$(TARGET_ABI_DIR))
+
 QEMU_CFLAGS+=-I$(SRC_PATH)/linux-user -I$(SRC_PATH)/linux-user/$(TARGET_ABI_DIR)
 obj-y = main.o syscall.o strace.o mmap.o signal.o thunk.o \
       elfload.o linuxload.o uaccess.o gdbstub.o
@@ -122,7 +123,8 @@ endif #CONFIG_LINUX_USER
 
 ifdef CONFIG_DARWIN_USER
 
-VPATH+=:$(SRC_PATH)/darwin-user
+$(call set-vpath, $(SRC_PATH)/darwin-user)
+
 QEMU_CFLAGS+=-I$(SRC_PATH)/darwin-user -I$(SRC_PATH)/darwin-user/$(TARGET_ARCH)
 
 # Leave some space for the regular program loading zone
@@ -147,7 +149,8 @@ endif #CONFIG_DARWIN_USER
 
 ifdef CONFIG_BSD_USER
 
-VPATH+=:$(SRC_PATH)/bsd-user
+$(call set-vpath, $(SRC_PATH)/bsd-user)
+
 QEMU_CFLAGS+=-I$(SRC_PATH)/bsd-user -I$(SRC_PATH)/bsd-user/$(TARGET_ARCH)
 
 obj-y = main.o bsdload.o elfload.o mmap.o signal.o strace.o syscall.o \

Makefile.user

@@ -6,11 +6,7 @@ include $(SRC_PATH)/rules.mak
 
 .PHONY: all
 
-# Do not take %.o from $(SRC_PATH), only %.c and %.h
-# All %.o for user targets should be built with -fpie, when
-# configured with --enable-user-pie, so we don't want to
-# take %.o from $(SRC_PATH), since they built without -fpie
-vpath %.c %.h $(SRC_PATH)
+$(call set-vpath, $(SRC_PATH))
 
 QEMU_CFLAGS+=-I..
 

pc-bios/optionrom/Makefile

@@ -5,7 +5,8 @@ all: build-all
 include ../../config-host.mak
 include $(SRC_PATH)/rules.mak
 
-VPATH=$(SRC_PATH)/pc-bios/optionrom
+$(call set-vpath, $(SRC_PATH)/pc-bios/optionrom)
+
 .PHONY : all clean build-all
 
 CFLAGS := -Wall -Wstrict-prototypes -Werror -fomit-frame-pointer -fno-builtin

rules.mak

@@ -39,6 +39,8 @@ quiet-command = $(if $(V),$1,$(if $(2),@echo $2 && $1, @$1))
 cc-option = $(if $(shell $(CC) $1 $2 -S -o /dev/null -xc /dev/null \
               >/dev/null 2>&1 && echo OK), $2, $3)
 
+set-vpath = $(if $1,$(foreach PATTERN,%.c %.h %.S, $(eval vpath $(PATTERN) $1)))
+
 # Generate timestamp files for .h include files
 
 %.h: %.h-timestamp

tests/Makefile

@@ -1,5 +1,6 @@
 -include ../config-host.mak
-VPATH=$(SRC_PATH)/tests
+
+$(call set-vpath, $(SRC_PATH)/tests)
 
 CFLAGS=-Wall -O2 -g -fno-strict-aliasing
 #CFLAGS+=-msse2